Fix error wording

Use 'saltenv' instead of 'environment'
Make gitfs_base configurable on a per-repo basis

Also fixed a regression, present only in the develop branch, where
ordering of gitfs remotes was not preserved.
Add info on per-remote gitfs_base to master docs
Fix 3835d30096a92c28aa19ae18114d6a4262748742

This commit breaks gitfs for non-gitpython providers, fixed the source
of the URI for the log message. Also simplified logic from this commit.
another error wording fix
Also require git CLI command when verifying gitpython

We can't be certain that packages have proper dependencies
Merge pull request #11558 from terminalmage/issue11347

Make gitfs_base configurable on a per-repo basis